Electrochemical plating cell with a counter electrode in an isolated anolyte compartment

Abstract

A fluid processing cell for depositing a conductive layer onto a substrate is provided. The cell includes a catholyte solution fluid volume positioned to receive a substrate for plating, a first anolyte solution fluid volume at least partially ionically separated from the catholyte solution fluid volume, an anode assembly positioned in the first anolyte solution fluid volume, a second anolyte solution fluid volume, the second anolyte solution fluid volume being electrically isolated from the first anode solution fluid volume and at least partially in ionic communication with the cathode solution fluid volume, and a cathode counter electrode positioned in the second anolyte solution volume.

1 . An electrochemical plating cell, comprising: 
 a fluid container having an ionic membrane positioned across the fluid container, the ionic membrane being positioned to fluidly separate a catholyte volume from a first anolyte volume in the fluid container;    an anode assembly positioned in fluid communication with the first anolyte volume;    a cathode substrate support member positioned to support a substrate at least partially in the catholyte volume for a plating process;    a counter electrode positioned in fluid communication with a second anolyte volume, the second anolyte volume being electrically separated from the first anolyte volume; and    a vent conduit positioned in fluid communication with the catholyte volume, the vent conduit being in ionic communication with the second anolyte volume.    
   
   
       2 . The plating cell of  claim 1 , wherein the first anolyte volume is electrically isolated from the second anolyte volume by an electrically insulating partition.  
   
   
       3 . The plating cell of  claim 1 , wherein the vent conduit further comprises an annular vent nozzle formed into the fluid container at a position adjacent a perimeter of the substrate during the plating process.  
   
   
       4 . The plating cell of  claim 3 , wherein the vent conduit containing electrolyte solution is in electrical communication with the counter electrode.  
   
   
       5 . The plating cell of  claim 4 , wherein the vent conduit extends across the ionic membrane.  
   
   
       6 . The plating cell of  claim 5 , wherein the second anolyte volume is positioned in communication with a lower surface of the ionic membrane adjacent the vent conduit.  
   
   
       7 . The plating cell of  claim 5 , further comprising: 
 a catholyte supply conduit in fluid communication with the catholyte volume and the vent conduit;    a first anolyte supply conduit in fluid communication with the first anolyte volume;    a first anolyte drain conduit in fluid communication with the first anolyte volume;    a second anolyte supply conduit in fluid communication with the second anolyte volume; and    a second anolyte drain conduit in fluid communication with the second anolyte volume.    
   
   
       8 . The plating cell of  claim 5 , wherein the vent conduit is configured to supply cathodic electrical flux to an area proximate the perimeter of the substrate during a plating process.  
   
   
       9 . The plating cell of  claim 1 , wherein the counter electrode is in electrical communication with a cathodic terminal of a power supply.  
   
   
       10 . The plating cell of  claim 1 , wherein the membrane comprises a cationic membrane.  
   
   
       11 . The plating cell of  claim 1 , wherein the counter electrode comprises an annular conductive member.  
   
   
       12 . A fluid processing cell for depositing a conductive layer onto a substrate, comprising: 
 a catholyte solution fluid volume positioned to receive a substrate for plating;    a first anolyte solution fluid volume at least partially ionically separated from the catholyte solution fluid volume;    an anode assembly positioned in the first anolyte solution fluid volume;    a second anolyte solution fluid volume, the second anolyte solution fluid volume being electrically isolated from the first anode solution fluid volume and at least partially in ionic communication with the cathode solution fluid volume; and    a cathode counter electrode positioned in the second anolyte solution volume.    
   
   
       13 . The fluid processing cell of  claim 12 , further comprising a cathode electrode vent positioned in an upper portion of a basin containing the catholyte solution fluid volume, the cathode electrode vent being configured to electrically connect the cathode counter electrode and catholyte solution fluid volume.  
   
   
       14 . The fluid processing cell of  claim 12 , further comprising an ionic membrane positioned between the cathode solution fluid volume and the first anode solution fluid volume and between the cathode solution fluid volume and the second anode solution fluid volume.  
   
   
       15 . The fluid processing cell of  claim 13 , wherein the cathode electrode vent comprises an annular opening in a wall defining the cathode solution fluid volume, the annular opening being configured to conduct electrical flux from the cathode counter electrode to the anode.  
   
   
       16 . The fluid processing cell of  claim 15 , wherein the annular opening is positioned adjacent a perimeter of the substrate being processed and is configured to minimize electrical flux near the perimeter of the substrate.  
   
   
       17 . The fluid processing cell of  claim 12 , wherein the anode assembly comprises a plurality of anode segments.  
   
   
       18 . The fluid processing cell of  claim 12 , wherein the cathode counter electrode is in electrical communication with a cathode terminal of a power supply.  
   
   
       19 . The fluid processing cell of  claim 18 , wherein the cathode terminal of the power supply is in electrical communication with the substrate and where the anode terminal of the power supply is in electrical communication with the anode assembly.  
   
   
       20 . An electrochemical plating cell, comprising: 
 a fluid basin having an ionic membrane positioned across a middle portion of the basin, the ionic membrane separating the fluid basin into an upper catholyte volume and a lower anolyte volume;    an anode assembly positioned in the lower anolyte volume;    a cathode substrate support member removably positioned in the catholyte volume;    a counter electrode positioned in an isolated anolyte volume, the isolated anolyte volume being positioned below the ionic membrane and not in direct electrical communication with the lower anolyte volume; and    a counter electrode vent positioned in an upper portion of the fluid basin at a position proximate an edge of a substrate being plated in the fluid basin, the counter electrode vent being in electrical communication with the counter electrode via a fluid conduit.    
   
   
       21 . The electrochemical plating cell of  claim 20 , further comprising a power supply having a cathodic terminal in electrical communication with a substrate support member and the counter electrode, and an anodic terminal in electrical communication with the anode assembly.  
   
   
       22 . The electrochemical plating cell of  claim 20 , wherein the fluid conduit communicates with an upper surface of the membrane that opposes the counter electrode.